HANG TIME NEW JERSEY – Last season’s San Antonio Spurs had the best record in the Western Conference at 50-16. This season’s Spurs have the best record in the Western Conference at 52-16. It’s basically the same roster with almost the same exact record.
But it’s not the same team, really. And this Spurs team is better suited to win a championship.
Earlier this month at the MIT Sloan Sports Analytics Conference, Spurs general manager R.C. Buford was asked about how open-minded Spurs coach Gregg Popovich is in regard to analytics. Buford noted how Popovich liked how the numbers often confirmed his basketball beliefs, like the importance of corner 3-pointers. And then Buford talked about how the Spurs dug into the numbers in the offseason to see how they can get better defensively.
“This summer, we looked at our defensive efficiency, which for years had been very high. And last year, we went in the 10-15 range. And I think we were valuing some things that weren’t nearly as important as the data showed us. We learned from the Celtics.
“While they were really high in defensive efficiency, they weren’t very high in defensive rebounding. And that was a big part of where our emphasis was, and it made us question is that really where we should be paying attention. And those were discussions that were then brought to Pop from our coaches and from our analytics team. And some great discussions came from that, that ended up having us reevaluate what was important to us.”
The Spurs ranked 11th defensively, allowing 100.6 points per 100 possessions, last season. But that wasn’t just a single step backward for the their defense. When you compare their defensive efficiency with the league average, they had actually regressed each of the last eight years.
Spurs defense, previous nine seasons
DefRtg = Points allowed per 100 possessions
Now, the 2003-04 Spurs were one of the best defensive teams in NBA history, allowing 8.5 points per 100 possessions fewer than the league average. So there was nowhere to go but down. And San Antonio continued to rank in the top three on that end for four more seasons, winning championships in 2005 and 2007.
But continuous regression over the years led them to eventually drop out of the top 10 defensively, which is not where you want to be if you want to contend for a championship. Of the last 22 teams to make The Finals, only one – the 2005-06 Mavs – wasn’t a top 10 defensive team in the regular season. Six of the 22 ranked outside of the top 10 offensively.
The Spurs’ identity changed quite a bit over the years. And while they certainly became more enjoyable to watch as they improved offensively – they ranked No. 1 in offensive efficiency last season – they became less qualified to win a championship. So a change was needed to stop their downward defensive trend.
Better to be good at the right things than great at the wrong things
There are four factors that effect efficiency on either side of the ball: Shooting, rebounding, turnovers and free throws. Last year, both the Celtics and Spurs were top five in two of those four categories defensively, but Boston was a much better defensive team overall, allowing over five points per 100 possessions fewer than San Antonio.
Celtics and Spurs defense, 2011-12
OppeFG% = Opponent effective field goal percentage = (FGM + (0.5 * 3PM)) / FGA
DREB% = Percentage of available defensive rebounds obtained
OppTmTOV% = Opponent turnovers per 100 possessions
OppFTA Rate = FTA/FGA
The Spurs were an excellent defensive rebounding team and did a great job of keeping their opponents off the free-throw line. But there’s a much stronger correlation between DefRtg and OppeFG% than there is between DefRtg and any of the other three factors. The most important thing you can do defensively is make your opponent miss shots from the field. And the Spurs just didn’t do that well enough.
So, using the Celtics for comparison, Popovich and crew went back to the drawing board, knowing they needed to adjust their defensive priorities. Contesting shots became the new focus, even if it meant more fouls or fewer rebounds.
And being more aggressive in challenging shots is logical, because league-wide free throw rate has dropped each of the last seven seasons and is now at its lowest mark (0.271) since the 1973-74 season. Whether it’s because teams are taking more threes or because fouls are being called differently the last few years, there’s less risk in contesting shots than there was 10 years ago.
More contested shots = better defense
The Spurs’ plan has worked. While they’ve regressed a little in both defensive rebounding percentage and opponent free throw rate, they’ve jumped from 11th to third in defensive efficiency, because they’ve defended shots better and forced more turnovers.
Spurs defense, last two seasons
What’s interesting is that the Spurs’ defense isn’t forcing less efficient shots. Their opponents are actually taking a greater percentage of their shots from the restricted area and the corners (the most efficient shots on the floor) than they did last season.
But San Antonio is defending most areas of the floor better than they did last year. In particular, they’re defending the paint much better.
Spurs’ opponent FG%, by area, last two seasons
|Above the Break 3||35.6%||25||33.6%||7||-2.0%|
The key ingredient comes from Brazil
A big key has been the improvement from Tiago Splitter, who has been the full-time starter next to Tim Duncan since mid-December, and whose minutes have increased about 5 1/2 minutes per game from last season.
With Duncan and Splitter on the floor together, Spurs opponents have shot just 43.7 percent in the paint. That’s the lowest mark for any two-man combination that has defended at least 500 paint shots all season.
Lowest opponent FG% in the paint, two-man combinations
|Duncan & Splitter (SAS)||229||524||43.7%|
|Sanders & Dunleavy (MIL)||246||553||44.5%|
|Hibbert & George (IND)||594||1,310||45.3%|
|Hibbert & Stephenson (IND)||461||1,016||45.4%|
|Hibbert & Hill (IND)||581||1,274||45.6%|
Minimum 500 FGA
The Spurs’ defense has allowed a measly 91.9 points per 100 possessions in the 648 minutes that Duncan and Splitter have shared the floor this season and just 87.4 in 477 minutes with Duncan, Splitter and Kawhi Leonard on the floor. That’s a ridiculously good defensive trio.
Opponents have scored 95.3 in Splitter’s 1,662 minutes total. Only five players who have logged at least 1,000 minutes (two for Memphis, two for Indiana and the Clippers’ Lamar Odom) have a lower on-court DefRtg.
It may all come down to defending OKC
Overall, this season’s San Antonio defense is 4.2 points per 100 possessions better than the league average. So they’ve finally reversed their eight-year, downward trend and are playing their best defense in five seasons.
Allowing 1.9 fewer points per 100 possessions than last season, the Spurs are the sixth most improved defensive team in the league. And while five other teams have made bigger jumps, the Spurs’ improvement could ultimately be the most important, because they already had a championship-caliber offense and it was on the defensive end of the floor where they lost the final four games of last year’s Western Conference finals.
In the regular season last year, 15 teams defended the Oklahoma City Thunder better than the Spurs, who allowed OKC to score 105.9 points per 100 possessions in their three regular season meetings and 110.4 in the playoffs. This year, only one team has defended the Thunder better.
Best defense vs. Oklahoma City, 2012-13
OffRtg = Points scored per 100 possessions
NetRtg = Point differential per 100 possessions
Oklahoma City has an effective field goal percentage of just 45 percent against the Spurs this season, down from 52 percent in last season’s nine total meetings. In particular, Russell Westbrook and Thabo Sefolosha have shot much worse against the Spurs than they did last season. Westbrook has shot just 5-for-16 in the paint with Splitter on the floor this season.
Splitter played just 53 minutes in last year’s conference finals, 10th most on the Spurs and 94 fewer than Boris Diaw. But he played 34 minutes in the Spurs’ 105-93 victory over the Thunder on March 11, and was a plus-24. OKC scored 41 points in his 14 minutes on the bench, but just 52 in his 34 minutes on the floor.
The Spurs’ defense against quality opponents goes far beyond their three games against the Thunder. In games played between current Western Conference playoff teams, San Antonio has been much better defensively than any of the other seven, including the Grizzlies, who rank second in defensive efficiency overall.
Best defense, games played between current West playoff teams
Tony Parker could return from his sprained ankle on Friday, when the Spurs host the Jazz. With Manu Ginobili playing more consistently of late, San Antonio looks to be at full strength in control of the No. 1 seed in the West once again. And more important than what they’re doing offensively is how well they’ve defended this season.
So dismiss the Spurs as a regular season team at your own peril. They may seem like the same team on the surface, but the numbers tell a much different story.